Hydraulic and resilient cushioned railway car draft assembly



y 1962 w. T. BLAKE 3,047,162

HYDRAULIC AND RESILIENT CUSHIONED RAILWAY CAR DRAFT ASSEMBLY Filed Jan.16, 1961 6 Sheets-Sheet l Fig.2

INVENTOR William T. Bloke ATTORNEY W. T. BLAKE July 31, 1962 HYDRAULICAND RESILIENT CUSHIONED RAILWAY CAR DRAFT ASSEMBLY 6 Sheets-Sheet 2Filed Jan. 16, 1961 INVENTOR WiHiom I. Blake BY W RN M

ATTORNEY July 31, 1962 3,047,162

HYDRAULIC AND RESILIENT CUSHIONED RAILWAY CAR DRAFT ASSEMBLY w. T. BLAKE6 Sheets-Sheet 5 Filed Jan. 16, 1961 INVENTOR Willibm T. Blake BYfl/m,%.

W ATTORNEY w. T. BLAKE 3,047,162

HYDRAULIC AND RESILIENT CUSHIONED RAILWAY CAR DRAFT ASSEMBLY July 31,1962 6 Sheets-Sheet 4 Filed Jan. 16, 1961 .Q% Q R OE xm kw QM m I I lI". III. E IIIIXV nnnn l nn Uflllll. m B T. f m m w J H M\....||i..|.|.n. m+ mh ww QR \w an 50 h. V /WM .m\ W .Qfim R Q5 NW NE MmQ NM .Qm A w \x\ k 1 -MNN QM r 6% \V .QN MN I I] w 1\ Wm QM s mm mm mmm. MM mm an R MM t ATTORNEY July 31, 1962 w. T. BLAKE HYDRAULIC ANDRESILIENT CUSHIONED 'RAILWAY CAR DRAFT ASSEMBLY 6 Sheets-Sheet 5 FiledJan. 16, 1961 INVENTOR William T. Bloke July 31, 1962 w. T. BLAKE3,047,162

HYDRAULIC AND RESILIENT CUSHIONED RAILWAY CAR DRAFT ASSEMBLY Filed Jan.16, 1961 6 Sheets-Sheet 6 Fig. l2

INVENTOR William T. Bloke ATTORNEY 3,047,162 Patented July 31, 19,62

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HYDRAULIC AND RESILIENT CUSI-HONED RAILWAY CAR DRAFT ASSEMBLY William T.Blake, 4424 Morris Court, Fort Worth, Tex. Filed Jan. 16, 1961, Ser. No.83,021 10 Claims. (Cl. 2138) This invention relates to railway car draftassemblies, and more particularly to railway car draft assembliesutilizing combined hydraulic and resilient cushioning to absorb theshock forces encountered in the movement of railroad cars.

The railway industry is constantly seeking a solution to the problem ofdamage to rolling stock and to car lading resulting from the severeshocks to which railway cars are subjected in normal movement. Railwayfreight cars, and their contents in particular, are subject to severeimpact forces when a train is made up in the freight yards by couplingfree-rolling, individual freight cars into a stationary car or group ofstationary cars. Additional shocks are imparted to the cars and theircontents when a train is in motion due to the slack that exists betweenthe couplers of each car. When a train is started into motion, each caris jerked by the car ahead and, upon braking a train to a stop, each caris bumped by the car behind it, thus imparting additional damagingshocks to the railway cars and their contents.

In my copending application Serial No. 41,586, filed July 8, 1960, forRailway Car Draft Appliance, there is disclosed a draft appliance forrailway cars especially adapted to be mounted in the end of the carscenter sill which effectively cushions the impacts and shocksencountered in train operation.

The present invention relates to an improved railway draft appliancethat may effectively, if desired, utilize portions of the draftappliance disclosed in my beforementioned copending application.

An object of the invention is to provide a draft appliance for railwaycars adapted to reduce appreciably the impacts or shocks exerted onrailway cars and their contents when such cars are made up into trainsand the trains are moved upon the tracks.

Another object of the invention is to provide an improved hydraulicallybuffered draft appliance having a resilient cushion assembly cooperatingtherewith in a new way.

Another object is to provide such a draft appliance that is capable ofbeing readily attached to the center sill of a conventional railway car.An additional object of the invention is to provide an improved draftappliance having a cooperating resilient cushion assembly coupled to ahydraulic buffer mechanism in the railway car so that the buffermechanism will function properly under all conditions of train operationand so that the buffer mechanism will be properly protected from unduestresses.

A particular object of the invention is to provide an improved draftappliance utilizing a combination of a double-acting hydraulic buffermechanism and resilient cushion assemblies for absorbing the shockforces to which railway cars are subjected.

An important object of the invention is to provide additional cushioningmeans for railway cars equipped with double-acting hydraulic buffermechanisms.

A further object of the invention is to provide a secondary shockabsorbing assembly that may be conveniently attached to railway carsequipped with existing primary shock absorbing mechanisms.

The foregoing, and other aims, objects, and advantages of the inventionas may appear hereinafter, are realized in a railway car having a centersill member affixed to 2 the car and a sliding member longitudinallyslidably mounted in the center sill member. A car coupler is attached tothe sliding member. A double-acting hydraulic buffer mechanism has afixed'element and a moving element, one of the elements being attachedto the center sill member, and the other of the elements being attachedto the sliding member. Cooperating stop means on the center sill memberand the sliding member permit longitudinal movement of the slidingmember in the center sill member. Light-duty resilient means are'provided, acting between the center sill member and the sliding memberin at least one longitudinal direction, urging the sliding member to aneutral'position between its limits of travel. Heavy duty resilientmeans is mounted on one of the members. Lost motion coupler meanscouples the heavy-duty resilient means to the other of the members overa terminal portion of the total permitted movement of the slidingmember, the coupler means uncoupling the heavy-duty resilient means fromthe other of the members over an intermediate portion of the totalpermitted movement of the sliding member.

The object relating to a secondary shock absorber assembly for railwaycars is realized in an assembly including a box-like unitary structurehaving spaced apart bracket members forming the end walls thereof. Thebracket members provide central openings therein. A spring compressorelement abuts the inside wall of each of the brackets. Each springcompressor element has a reduced portion extending rearwardly therefromthrough the opening in the bracket members. A helical compression springis mounted in the structure between the compressor elements. A lostmotion coupler yoke is provided having an opening therein fitting overthe structure with opposite surfaces of the yoke abutting the outer endsof the compressor elements. The yoke provides a longitudinally extendingslot in one end thereof for receiving a draft gear key.

In the drawings:

FIG. 1 is a plan view of one end of a railway car center sill havinginstalled therein a draft appliance in accordance with the invention, aportion of the center Sill being broken away to show internal structure;

FIG. 2 is an elevational view of the assembly shown in FIG. 1 with aportion of the center sill being broken away to show internalconstruction;

FIG. 2a is a sectional view along line 2a2tz of FIG. 2;

FIG. 2b is a bottom view on an enlarged scale, of the assembly shown inFIGS. 1 and 2;

FIG. 3 is a vertical, longitudinal sectional view, on an enlarged scale,taken along line 33 of FIG. 1;

FIG. 4 is an elevational view of the assembly, on the same scale as FIG.3, showing portions of the secondary shock absorbing assembly in crosssection;

FIG. 5 is an elevational view of a portion ofthe appliance showing thedraft assembly in the full draft position;

FIG. 6 is an elevational view of a portion of the appliance showing thedraft assembly in the full buff position; FIG. 7 is a sectional viewalong line 7--7 of FIG. 4;

FIG. 8 is an enlarged sectional view along the. line 8 8 of FIG. 1; i

FIG. 9 is an elevational view of one end of a railway car center sillhaving installed thepeonanother form of draft appliance in accordancewith the invention, certain parts being shown in section and the draftappliance being in neutral position;

FIG. 10 is a plan view of the assembly of FIG. 9;

FIG. 11 is a sectional view along line 1 1-1-1 of FIG. 9;

FIG. 12 is an elevational view similar to FIG. 9 showing the draftappliance in the full draft position; and

FIG. 13 is an elevational view similar to FIG. 9 showing the draftappliance in the full buff position.

Referring to the drawings, particularly to FIGS. 1 and 2 thereof, therailway car draft appliance of the pres ent invention is shown as beinginstalled at one end of a conventional railway car center sill 20. Sincesuch a center sill is well known in the prior art, it will be understoodthat it provides the main support for the car body which is mounted ontop thereof and that it, in turn, is supported on the usual bolsters andtrucks, the wheels of which ride upon the track rails. The center sillhas longitudinal side walls 21 and 22 and a top plate 23. The centersill is open at the bottom and the side walls have outwardly extendingbottom flanges 24 and 25. As is conventional, the end 26 of the centersill is open. It will be understood that the other end of the centersill, not shown, is similarly constructed and is also open.

The draft assembly of the present invention is attached to the centersill 20 adjacent the open end thereof, as can be seen in FIGS. 1, 2 and3. A double-acting hydraulic buffer mechanism (designated generally 129in FIG. 3) is contained within a housing or sliding member 35 that islongitudinally slidably mounted in the open end of the center sill 20. Acar coupler 27 projects from the end of the housing and is connectedthereto by a coupler key 34. A cross plate 66 extending across thebottom of the center sill 20 supports the housing 35 within the centersill. The rearwardly extending piston rod 67 of the hydraulic buffermechanism is anchored to the center sill by anchor assembly 68. Asecondary shock absorbing assembly 45 is mounted on the outside of eachside wall of the center sill and engages the housing 35 through stopkeys 39 and 41. The housing and the associated hydraulicbuffer'mechanism are urged to a neutral position by a return springmechanism 64 mounted underneath cross plate 66.

The structure by which buff and draft forces are applied from thecoupler 27 directly to the center sill will be described with referenceto FIGS. 1 through 4 and 7. As can be seen in FIGS. 1 and 2, the sidewalls 21 and 22 of the center sill are strengthened by reinforcingplates 28 and 29 welded to the side walls. A central longitudinal slot30 is cut through the reinforcing plate 28 and side wall 21, this slotbeing open, as shown at 31, through the end 26 of the center sill. Upperand lower longitudinal slots 32 and 33 are also cut through thereinforcing plate and side walls, these slots being closed at both ends.Corresponding slots are provided in the reinforcing plate 29 and centersill side wall 22 laterally opposite the aforementioned slots. A couplerkey 34 extends through the central slots 30 and transversely through thehousing or sliding member 35, as seen in FIG. 7. The coupler key 34 issnugly received in keyways 36 in the sides of the housing 35. Thecoupler key 34 passes with a fairly loose fit through a transverse slot37 in the shank 38 of the coupler 27, as shown in FIG. 3, so that thecoupler may pivot to a limited extent on the key.

An upper stop key 39 passes transversely through the housing and throughthe upper longitudinal slots 32 in the side walls of the center sill.This key is loosely received in the slots and fits snugly in keyways 40in the side walls of housing 35. A lower stop key 41, similar to the key39, is similarly associated with the lower longitudinal slots 33 in theside walls of the center sill and with the housing 35. The keys 39 and41 are prevented from moving transversely to any substantial extent byintegrally formed shoulders 42 on one end, as shown in dotted outline inFIG. 4. Retainer pins 43 are inserted through holes provided in theopposite ends of the keys and retained therein by cotter keys 44. Thecoupler key 34 is held within its cooperating slots by similar retainerpins received in openings at each end thereof.

When buff forces are received by the coupler 27, they are transmitted tothe housing 35 by contact between the inner end 80 of the coupler shankand a transverse partition 75 in the housing, as may be seen in FIG. 3.The stop keys 39 and 41 move rearwardly with the housing in slots 32 and33 and the coupler key 34 moves rearwardly in slot 30. If the impactforces exceed the combined cushioning capacity of the hydraulic buffermechanism and the secondary shock absorbing assembly, the housing flange65 contacts the reinforced end 26 of the center sill to transmit theunabsorbed force directly to the center sill 20. Contact is made betweenthe housing flange and center sill end before the keys 34, 39 and 41reach the rearward end of the slots 30, 32 and 33, respectively. Uponapplication of draft forces to the coup ler, the coupler key 34transmits the force to the housing 35. As the housing moves forward, thekey 34 moves partially out of slot 30 through the open end 31 thereof.The stop keys 39 and 41 contact the forward ends of the slots 32 and 33in the center sill side wall to apply the draft force directly to thecenter sill if the draft forces exceed the combined cushioning capacityof the hydraulic mechanism and the secondary cushion assembly.

The construction of the secondary shock absorbing assemblies, designatedgenerally 45, will now be described with reference to FIGS. 1, 2, 2a, 4and 8.

A secondary shock absorbing assembly 45 is fixed to each reinforcingplate 28 and 29 on the side walls 21 and 22 of center sill 20. Eachassembly has a longitudinally extending lost motion coupler plate 46which provides an upper slot 47 and a lower slot 48 positioned parallelto the upper slot 32 and lower slot 33 in the reinforcing plate and sidewall of the center sill. The slots in each pickup plate loosely receivethe respective stop keys 39 and 41 for limited longitudinal movementtherein. The coupler plate slots 47 and 48 have a shorter longitudinalopening than the corresponding slots 32 and 33 in the reinforcing plateand center sill side wall, as can be seen in FIG. 2 and 4. Each couplerplate has a reinforcing shoulder member 49 formed adjacent tothe forwardportion of slots 47 and 48, as may be seen in FIGS. 1 and 2a, theshoulder members being open at the rear to permit the keys 39 and 41 tomove in the slots 47 and 48. A generally rectangular recess 50 isprovided in the coupler plate intermediate the upper and lower slots topermit access to the coupler key 34. Referring now to FIG. 4, thecoupler plate provides an integrally formed, rearwardly extending shaft51 which has a shoulder 52 adjacent its forward end. The shaft iscylindrical, as may be seen in FIG. 8, from the shoulder 52 to therearward end thereof. A vertically extending forward bracket member 54and a spaced apart rearward bracket member 55 are Welded to a side plate56, to a top plate 57 and to a bottom plate 58 to provide a rigidbox-like bracket structure, as shown in FIGS. 4 and 8. The forward andrearward bracket members provide cylindrical openings therethroughfreely receiving the shaft 51. The side plate 56 is fixed to thereinforcing plate 29 'by welding or other suitable means. A cylindricalcollar 59 is slidably received on shaft 51 and abuts the shoulder 52thereon, and also abuts the inner face of bracket member 54. A similarcollar 60 is received on the rear of the shaft and abuts the inner faceof the rearward bracket member 55. A heavy-duty helical compressionspring 61 is mounted around the shaft 51 between the collar members 59and 60. A nut 62 and washer 63, which are freely received in the openingprovided in the rear bracket member 55, abut the rear face of thecylindrical collar 60.

The draft assembly is equipped with a return spring mechanism designatedgenerally 64, as shown in FIGS. 2, 2b and 6. The return spring mechanism64 restores the housing 35 to a neutral position following theapplication of buff or draft forces to the coupler 27. Housing flange 65has a depending ear 83, providing a hole therethrough, in which isreceived a tie rod 84. The tie rod has a collar abutting the inside ofthe ear 83 and is fixed to the ear by nut 86 received on the threadedend of the tie rod. Referring now specifically to FIG. 2b, it can beseen that the tie rod 84 passes freely through a hole 87 in a bracket88, which is welded or otherwise suitably secured to the bottom of across plate 66. The rear end of the tie rod is slidably received in ahole 89 in a yoke bar 90. A nut 91, threaded on the inner end of the tierod, bears against the rear surface of yoke bar 9%.

The yoke bar is slidable on a pair of guide rods 92 and 93 fixed attheir front ends to the bracket 88 and having nuts 94 and 95,respectively, threaded to the rear end of the guide rods. Helicalsprings 96 and 97 surround the guide rods and are compressed betweenbracket 88 and yoke bar 90. A longer compression spring 98 surrounds tierod 84 and is compressed bet-ween collar 85 and the front face of theyoke bar 90. This spring 98 passes freely through the hole 87 in bracket88.

In the full draft position, as seen in FIG. 2b, the short springs 96 and97 are under compression and tend to move the yoke bar 90 rearwardlyinto abutment with the nuts 94 and 95 to restore the housing 35 to theneutral position seen in FIG. 2. In the full butf position, as seen inFIG. 6, the tie rod 84 moves to a position wherein the nut 91 is spacedrearwardly from the yoke bar and the long spring 98 is under compressionbetween the collar 85 and the yoke bar 90. When the buff forces areremoved from the coupler, the long spring 98 acts to restore the housingto the neutral position. The return spring mechanism 64- is convenientlylocated beneath the fixed center sill of the car for easy access in caseof needed adjustment or repair.

The springs 96, 97 and 98 of the return mechanism 64- are relativelylight-duty compression springs as compared to the heavy-duty cushionassembly spring 61. It is only necessary that the return springs havesufficient strength to move the housing 35 and its associated hydraulicmechanism to the neutral position after the draft assembly absorbs buffor draft forces.

Between the forward and rearward limits of movement of the housing 35,housing motion is cushioned by a double-acting hydraulic mechanism.Referring to FIG. 3, the hydraulic mechanism shown has a piston rod 67anchored to the center sill on one end by an anchor assembly, designatedgenerally 68. The piston rod carries a piston 69 slidable in a workingcylinder 70. The ends of the working cylinder are closed by a frontcylinder head 71 and a rear cylinder head 72. The forward end of thepiston rod is slidably received in a central opening provided in thefront cylinder head and the rear end of the piston rod is slidablyreceived in a like opening provided in the rear cylinder head. TheWorking cylinder is mounted in a sealed chamber 73 in the housing 35.The chamber is closed at the rear by a rear closure plate 74 whichprovides an opening for the piston rod and is welded to the housing 35.The front end of the chamber is closed by a transverse partition 75forming a part of the housing. A flexible oellows 76 protects the pistonrod from external dust and moisture. A compensating device 77compensates for volume changes occasioned by movement of the piston rodinto and out of the chamber and by temperature changes. The chamber 73and the working cylinder 70 are completely filled with a suitablehydraulic fluid.

The foregoing brief description of the double-acting hydraulic mechanismis believed sufficient to acquaint those skilled in the art with thestructure of the mechanism. Reference is made to the aforementionedcopending application for a more complete disclosure of the hydraulicmechanism.

The operation of the draft appliance of the present invention will nowbe described with reference particularly to FIGS. 2, 3, 5 and 6. Inmaking up a train of railway cars, the cars are coupled together bymoving a car into coupling engagement with a stationary car. The movingcar may strike the stationary car at speeds as low as /2 or 1 mile perhour or as high as or 12 miles per hour. The force of impact, unlessadequate- 1y cushioned, may cause damage to the cars and to theirlading. Consider a stationary car equipped with the draft appliance ofthe present invention having the several parts of the appliance in theneutral position as shown in FIGS. 2 and 3. When a moving carapproaching from the right strikes the coupler 27, the coupler shank 38is moved rearwardly until the inner end of the coupler shank strikes thetransverse partition 75 of the housing 35. Rearward movement is impartedto the housing 35 which slides within the center sill 20, compressingthe return spring mechanism 64. The piston 69, being anchored throughpiston rod 67 and anchor structure 68 to the center sill 29, remainsrelatively stationary and the housing 35 and working cylinder moverearwardly with respect to the piston. Hydraulic fluid within theworking cylinder in front of the piston is forced out through the fixedopenings 78 in the cylinder which are forward of the piston, therebyabsorbing energy and cushioning the rearward movement of the housing.Hydraulic fluid returns to the working cylinder behind the pistonthrough openings 73 as they are uncovered by the piston and also throughthe inwardly opening check valve 79 in the rear cylinder head 72. Thedecrease in effective internal volume'of the hydraulic system due topiston displacement'thereinto is compensated by the compensating device77 which contracts in volume and prevents any substantial increase inpressure in the sealed chamber 73 surrounding the working cylinder.

At low coupling speeds, when the impact against the coupler 27 is notgreat,'the fixed openings 78 provide sufficient throttling to absorb theenergy. At higher coupling impacts, the ball check valve 81 in thepiston 69 opens to afford passage for some of the hydraulic fiuidthrough the piston from front to rear, thus relieving dangerously highpressures in the Working cylinder and, at the same time, absorbingadditional impact energy. The small fixed opening 82 in the piston 69permits a small amount of fluid to flow through the piston.

As housing 35 moves rearwardly into the center sill 213, stop keys 39and 41 move rearwardly in slots 32, 33 and 47, 48 provided in the centersill side wall 21 and reinforcing plate 28 and the coupler plate 46respectively, as can be seen in FIG. 2. imparted to the coupler are ofmoderate intensity, the hydraulic mechanism will arrest the rearwardmovement of the housing before the stop keys 39 and 41 engage therearward ends of slots 47 and 48 in the coupler plate 46. A higherimpact force on the coupler will move the stop keys into engagement withthe rearward slot ends of the coupler plate forcing the coupler platerearwardly and causing the shoulder 52 of the shaft 51 to force thecollar 59 against compression spring 61, as shown in FIG. 6. Thus, thesecondary cushion spring assembly 45 provides additional shock absorbingmeans when the forces applied are greater than can be absorbed by thehydraulic mechanism. Under extremely heavy buif forces that exceed thecombined shock absorbing capacity of the hydraulic mechanism and thesecondary spring cushion assembly, the housing flange 65 contacts thereinforced end 26 of center sill 20 to transmit the unabsorbed forcedirectly to the center sill.

After the moving and stationary cars have been coupled, the returnspring mechanism 64 returns the housing to the neutral position of FIG.2.

When a train of cars has been made up and the train is started, draftforces on the coupler 27 urge the housing to move from the neutralposition of FIG. 2 to the fully extended position of FIG. 5. Energy isabsorbed largely by the throttling of the fluid through the fixedopening 82 in the piston and through the rearmost of the fixed openings78 in the side wall of the working cylinder '70. It will be understoodthat the check valve 79 in the rear cylinder head 72 is closed and thatfluid is returned to the Working cylinder in front of the piston throughfixed openings 78 and, if

If the buff forces.

required, through the inwardly opening check valve 79 in the frontcylinder head 71. The compensating unit 77 will expand, as required bywithdrawal of the piston from the housing, to prevent the formation of avacuum in the hydraulic system.

In the neutral position, as shown in FIGS. 1, 2 and 4, it can be seenthat the forward edge of the upper and lower stop keys 39, 41 arepositioned very close to the forward end of slots 47 and 48, and thereinforcing shoulder 49 of the lost motion coupler plate 46. Thus, thespring cushion assembly 45 is almost immediately engaged upon theapplication of draft forces to the coupler 27. As the stop keys moveforward with the housing 35, the lost motion coupler plate shaft 51moves forward through the openings in the bracket members 54 and 55, asshown in FIG. 5. The nut 62 and washer 63 afiixed to the end of shaft 51pick up collar 60 which,

in turn, compresses spring 61, thereby transmitting a portion of thedraft forces to compression spring 61. Under normal application of draftforces, the coacting hydraulic mechanism and secondary shock absorbingassembly are sufficient to absorb the full draft force. In very rareinstances, where the draft forces are in excess of the capacity of thecombined cushioning assemblies, the forward edge of stop keys 39, 41will strike the ends of slots 32, 33 to transmit the unabsorbed forcedirectly to the center sill 20. Upon the removal of draft forces fromthe coupler, the secondary shock absorbing assembly 45 will cooperatewith the return spring mechanism 64 to return the draft assembly to theneutral position of FIG. 1.

It is contemplated that the length of the slots 47 and 48 in the lostmotion coupler plate 46 may be varied over a considerable range toprovide any desired degree of cooperative cushioning by the hydraulicmechanism and the secondary cushion asembly 45. Coil springs of veryhigh compression strength are preferably used for the spring 61 toprevent the housing 35 and the center sill 20 from making solid contactexcept in instances involving extremely high bluff or draft forces.Standard railway truck coil springs may conveniently be used for coilspring 61.

In a specific exemplary construction of the present draft assemblyutilizing the hereinbefore described form of secondary cushioningassembly, the distance between the reinforced end 26 of the center silland the rearward face of the housing flange is 7 inches when the draftassembly is in the neutral position shown in FIG. 2. The slots 47 and 48are dimensioned to permit the rearward edges of the stop keys 39 and 41to move 6 inches to the rear in the slots before contacting the couplerplate to engage the helical spring 61. Thus, the first 6 inches ofrearward travel of the housing 35 is cushioned mainly by the hydraulicmechanism. The brackets and coupler plate shafts are positioned topermit a one inch rearward compression of the helical spring 61 beforethe housing flange 65 engages the reinforced end 26 of the center sill.Over the last one inch of travel, the housing is cushioned primarily bythe combined resistance of the hydraulic mechanism and the two helicalsprings 61, with a minor contribution from the return spring assembly64. The coil spring used on each side of the center sill in the cushionspring assemblies is the /2 inch diameter spring described in thespecification sheet of Recommended Practice of the Association ofAmerican Railroads for Freight Car Truck Springs, Total Travel 2 /2Inches, Alternate Standard, adopted 1947. The helical truck spring iscompressed 1 inch when placed between the collars 59 and 60 inside thebrackets. When under the 1 inch of additional compression in the fullbuff position, the twosets of helical truck springs exert aforwardacting force of 16,356 lbs. The return spring 98 contributes aforward acting force of 2,757 lbs., for a total forward acting force of19,113 lbs.

The draft assembly is dimensioned to permit a 1 inch maximum forwardmovement of the housing from the neutral position when draft force isapplied to the coupler. The brackets and a coupled plate shafts arepositioned to permit a 1 inch forward compression of the helical springs61 before the stop keys engage the forward ends of the slots in thereinforced side walls of the center sill. The two sets of helical trucksprings exert a rearward acting force of 16,356 lbs. The two draftreturn springs 96 and 97 are also compressed 1 inch and contribute arearward acting force of 4,734 lbs., for a total rearward acting forceof 21,090 lbs.

It can be seen that the draft assembly of the present inventionovercomes one of the major disadvantages of the resilient cushion typeof draft gear in that no snapback occurs after the draft assembly iscompressed by buff or draft forces. The secondary shock absorbingassemblies utilized in the present draft assembly are always under thecontrol of the double-acting hydraulic buffer mechanism. The dampingaction exerted by the hydraulic mechanism permits a soft, controlledreturn of the compressed springs to their neutral position without theusual violent rebound common to resilient cushion draft gear.

Other forms of cushion means, such as leaf springs or rubber shockabsorbers, are contemplated for use in the cushion assembly 45.

A modified form of draft appliance, including a different form ofsecondary shock absorbing assembly, will now be described with referenceto FIGS. 9 through 13.

It can be seen in FIGS. 9 and 10 that much longer side reinforcingplates 99 and 100 are fixed to each side of the fixed center sill 20than are used in the previously described form of the invention. Each ofthe reinforcing plates provides two vertically spaced openings 101 and102 to receive keys 103 and 104 which retain the piston rod anchorassembly within the center sill 20.

Referring to FIG. 9, a holder for the compression spring is formed bywelding a bottom plate 105, a top plate 106, a rearward bracket 107 anda forward bracket 108 into box-like structure. A separate box-likestructure is welded to each of the side reinforcing plates 99 and 100.The rearward and forward bracket members provide central cylindricalopenings 1G9 and 110, respectively. These openings receive the rearwardand forward cylindrical spring compressor members 111 and 112,respectively. A double helical coil spring 113 is mounted in compressionbetween the spring compressors and is retained therebetween by means ofannular shoulders 114 provided on the peripheries of each compressor.The double helical coil spring includes a heavy-duty outer coil 113a anda lighter-duty inner coil 113b,

A lost motion coupler yoke member 115 provides a rectangular cutoutsection which permits the yoke member to be loosely fitted over thespring box structure for longitudinal sliding movement thereon. The yokemember has a rearward end wall 131 and a forward end wall 132 whichsubstantially abut the outer ends of the rearward compressor 111 and theforward compressor 112, respectively. Each yoke member provides an upperslot 116 and a lower slot 117 positioned parallel to the slots 32, 33 inthe side wall and reinforcing plate. The slots 116 and 117 looselyreceive the respective stop keys 39 and 41 for limited longitudinalmovement therein. As in the case of the previously described shockabsorbing assembly, the present slots are longitudinally shorter thanthe corresponding slots in the reinforcing plate and side wall. Agenerally rectangular opening is provided in the forward section of theyoke member between the slotted portions, to permit access to thecoupler key 34. The yoke member has a triangular reinforcing fin 121 onthe rear portion to strengthen this part of the yoke.

Referring now to FIGS. 10 and 11, the yoke members are provided withtransverse, rectangular spacer plates 118 which serve to center the yokemembers over the spring compressors. The spacer plates are retained in aloose sliding position between the reinforcing plates on the center silland upper and lower projecting edge portions 9 v of each spring boxcover plate 119. The cover plates are removably attached to the springboxes by bolts 120. It is preferable to pack the interior of the springboxes with a heavy grease to lubricate the spring compressors and toprotect the springs from corrosion.

The lost motion coupler yoke member 115 is preferably made from steel bycasting, but it can be fabricated by milling heavy steel plate with thespacer plates attached by welding.

, A modified return spring mechanism, designated generally 122, isembodied in the assembly of FIGS. 9 to 13. It will be seen in FIG. 9that the mechanism includes a tie rod 123 slidably mounted in a fixedbracket 124 which is welded to the underside of a cross plate 66. A nut125 is threaded on the rear end of the tie rod and abuts the rearsurface of the bracket 124. A return spring 126 is coiled around the tierod and placed under compression between the bracket 124 and a collarmember 127 that is welded or threaded on the forward end of the tie rod.The tie rod and coil spring are slidably supported within a supportsleeve 128 that is welded to the cross plate 66 adjacent the open end ofthe center sill. The collar member 127 abuts the ear 83 on the housingflange 65, and has a turned-down forward section which is slidablyreceived in an opening in the car 83. The modified form of the returnspring mechanism does not have any draft return springs.

In operation, the modified form of secondary shock absorbing assemblyfunctions in a manner similar to the first described assembly. On buffimpact, the housing 35 moves rearwardly into the fixed center sill 20,the keys 39 and 41 move freely in the slots in the center sill sidewall, the reinforcing plate and the slots 116 and 117 in the yokemember, as can be seen in FIG. 9. If the impact is moderate, thehydraulic mechanism will arrest the rearward movement of the housing. Ifa heavy buff force is received, the housing will continue its rearwardmovement until stop keys 39 and 41 engage the yoke member at therearward end of slots 116 and 117. The forward end wall 132 of the yokemember contacts the forward spring compressor 112 and forces thecompressor rearwardly, compressing the double helical spring 113 againstthe rearward compressor 111, as is clearly shown in FIG. 13. Underextremely high buff forces, the housing flange 65 contacts thereinforced end 26 of the center sill to transmit any unabsorbed forcedirectly to the fixed center sill 26) before either the hydraulic orspring cushion mechanism goes solid.

In the neutral position, as shown in FIGS. 9, and 11, the forward edgeof stop keys 39 and 41 are positioned very close to the forward end ofslots 116 and 117 in the yoke member. Upon application of a draft forceto the coupler, the rearward end wall 131 of the yoke member almostimmediately engages the heavy-duty helical spring 113 through the rearspring compressor 111 to cushion the forward motion of the housing 35 incooperation with the hydraulic mechanism. If an extremely heavy draftforce is applied to the coupler, the spring 113 will be compressed untilthe forward edges of stop keys 39 and 41 strike the ends of the slots inthe reinforcing plates and center sill side walls to transmit theunabsorbed draft force directly to center sill 20. The draft assembly isshown in this maximum draft position in FIG. 12.

When the draft force is removed from the coupler, the double helicalsprings 113, acting through the yoke members 115, restores the housingto the neutral position of FIG. 9. As shown in FIG. 12, the housingflange ear 83 moves out of abutting engagement with the collar 127 ondraft pull-out. In the full buff position, shown in FIG. 13, the returnspring is under compression and upon removal of the butt force willreturn the housing to the neutral position. The forward return of thehousing is assisted by the double helical spring 113 until the forwardspring compressor contacts the forward bracket and then the returnspring mechanism 122 acts 1Q alone to move the housing forward to theneutral position.

In one specific exemplary construction of the present draft assemblyutilizing the modified form of secondary cushioning assembly, thedistance between the reinforced end 26 of the center sill and therearward face of the housing flange 65 is 8 inches when the draftassembly is in the neutral position shown in FIG. 9. The slots 116 and117 are dimensioned to permit the rearward edges of stop keys 39 and 41to move 5 inches to the rear in the slots before contacting the yokemember to engage the helical spring 113. Thus, the first 5 inches ofrearward travel of the housing 35 is cushioned solely by the hydraulicmechanism. The spring boxes and yoke members are positioned to permit a3 inch rearward compression of the helical springs 113 before thehousing flange 65 engages the reinforced end 26 of the center sill. Overthese last 3 inches of travel, the housing is cushioned primarily by thecombined resistance of the hydraulic mechanism and the two doublehelical coil springs, with a minor contribution from the return spring126. The coil spring used on each side of the center sill in the springcushion assemblies is a helical truck spring for 1,000 H.-P. dieselswitching locomotives, meeting the specification as set out inRecommended Practice of the Association of American Railroads, adopted1949. The helical truck spring is initially compressed 1 inch whenplaced'between the spring compressors in the spring box with thecompressors in the positions shown in FIG. 9. When under 3 inches ofadditional compression in the full buff position, the two sets ofhelical truck springs exert a total forwardly acting force of 50,450lbs. The single return spring contributes a forwardly acting force of3,285 lbs. for a total forwardly acting force of 53,735 lbs.

The draft assembly is dimensioned to permit a 2 inch maximum forwardmovement of the housing from the neutral position when draft force isapplied to the coupler. The yoke and compression members are constructedto permit a 2 inch forward compression of the two sets of helical trucksprings before the stop keys engage the forward ends of the slots in thereinforced side walls of the center sill. The two sets of helical trucksprings exert a rearwardly acting force of 37,648 lbs. when under theadditional 2 inch compression. As explained before, no cushioning forceis obtained from the return spring assembly in the modified arrangementwhen the draft assembly is forward of the neutral position.

In addition to the herein described helical springs, it is contemplatedthat the yoke type cushion assembly may be readily adapted to use othercushion means, such as leaf spring or rubber shock absorbers.

The draft appliance of the present invention provides an eflicientcushioning mechanism for all buff and draft shocks encountered in themake up and operation of a train of railway cars. The cooperation of thesecondary cushion assembly with the hydraulic shock absorbing mechanismprovides numerous benefits not attained by either type of shockabsorbing device acting alone. As stated hereinbefore, the present draftassembly overcomes the objectionable rebound which is common to theresilient cushion type of draft appliances. The hydraulic mechanismdampens the recoil of the springs and permits a gentle restoration ofthe draft assembly to its neutral position. The secondary shockabsorbing assembly functions over the terminal portion of the stroke ofthe hydraulic mechanism and provides a high resistance force to preventbuilding up high hydraulic pressure within the cylinder of the hydraulicmechanism. Thus, the hydraulic mechanism will have a longer lifeexpectancy with less maintenance being required. The lost motion couplerutilized in the present draft assembly allows the hydraulic mechanism tohave full control for absorbing buff impacts of moderate intensity andcouples the secondary cushion assemblies to the hydraulic mechanism onlywhen heavy buif forces are encountered. An advantage of the secondaryshock absorbing assembly of the present invention is its simpleconstruction and the ease with which it may be installed on existingrailway cars without extensive modifications to the cars. Any degree ofcooperation between the secondary shock absorbing assembly and thehydraulic mechanism may be obtained by varying the length of the slotsin the lost motion coupler. Further advantages may be obtained byvarying the strength of the helical springs utilized in the secondaryshock absorbing assemblies to suit the particular service for which therailway car is to be used. The present draft assembly can be readilymodified to provide secondary shock absorbers which function to absorbshocks received from one direction instead of both directions. Thesecondary shock absorbers may be modified to cushion buff forces aloneby providing open forward ends in the lost motion coupler slots so thatthe stop keys do not engage the lost motion coupler upon the applicationof draft forces to the car coupler. If it is desired to utilize thesecondary shock absorbers only when draft forces are applied to thedraft assembly, the slots in the lost motion coupler may be extended tothe rear so that no contact is made between the stop keys and therearward end of the slots. The modified form of the return springassembly has the advantage of eliminating two springs and otheraccessory parts from the previously used form of the return springassembly.

The utilization of the disclosed cushion assembly in a draft applianceemploying a primary hydraulic shock absorber greatly improves theability of the draft appliance to absorb severe shocks even when theassembly is under an existing draft or buff condition. For example, agroup of cars having hydraulic draft gears is coupled to an engine andthe train is moved rearwardly with sufiicient force to cause thehydraulic shock absorbers of all the cars to reach their limits oftravel and the cars to be in a state of relatively solid engagement. Ifthe train continues its rearward movement and couples into a standingcar or group of cars, the coupling impact will impose a severe shockforce to the solidly engaged forward cars. Consider the same situationwith the moving cars equipped with the draft assembly of the presentinvention, including the herein disclosed secondary shock absorbingassembly. When the engine couples into the first set of cars, the shockwill be initially absorbed by the hydraulic mechanism and then,additionally, by the secondary cushion mechanisms if the coupling forceis severe enough. The secondary cushion assemblies will store some ofthe impact energy in the cushion springs and, immediately after contact,this energy will be returned by the cushion springs to urge the draftassemblies to a position in which the hydraulic mechanism of each car iscapable of absorbing additional impact shock. Then, When the trainimpacts the standing car or group of cars, the draft assemblies of themoving cars are not in the solid condition and can absorb the impactforces. It can be readily seen that the secondary shock absorbingassemblies urge the draft assembly of the present invention to positionsto absorb shock forces regardless of the direction from which theseforces are received or the rapidity with which the shock forces occur.

The foregoing disclosure and description of the invention isillustrative and explanatory thereof and, in the light thereof, othermodifications will be apparent to those skilled in the art. Therefore,the present invention is to be limited only by the scope of the appendedclaims.

I claim:

1. In a railway car having a center sill member afiixed to the car, adraft assembly comprising: a sliding member longitudinally slidablymounted in said center sill member; a car coupler attached to saidsliding member; a doubleacting hydraulic bufier mechanism having a fixedelement and a moving element, one of said elements being attached to thecenter sill member and the other of said elements being attached to saidsliding member; cooperating stop means on said center sill member andsaid sliding member permitting limited longitudinal movement of saidsliding member in said center sill member; light-duty resilient meansacting between said center sill member and said sliding member in atleast one longitudinal direction urging said sliding member to a neutralposition between its limits of travel; heavy-duty resilient meansmounted on one of said members; and lost motion coupler means couplingsaid heavy-duty resilient means to the other of said members over aterminal portion of the total permitted movement of said sliding member,said lost motion coupler means uncoupling said heavy-duty resilientmeans from said other of said members over an intermediate portion ofthe total permitted movement of said sliding member.

2. in a railway car having a center sill member affixed to the car, adraft assembly comprising: a sliding member longitudinally slidablymounted in said center sill member; a car coupler attached to saidsliding member; a double-acting hydraulic buffer mechanism having afixed element attached to one of said members and a moving elementattached to the other of said members; cooper ating stop means on saidmembers permitting limited longitudinal movement between the elements ofsaid hydraulic mechanism; light-duty resilient means acting in at leastone longitudinal direction to urge said sliding member to a neutralposition between the limits of travel of the elements of said hydraulicmechanism; heavy-duty resilient means mounted on said fixed center sillmember; and lost motion coupler means coupling said heavyduty resilientmeans to said sliding member over a single terminal portion of the totalpermitted movement of said sliding member, said lost motion couplermeans uncoupling said heavy-duty resilient means from said slidingmember over the remaining portion of the total permitted movement ofsaid sliding member.

3. In a railway car having a center sill member atlixed to the car, adraft assembly comprising: a sliding member longitudinally slidablymounted in said center sill member; a car coupler attached to saidsliding member; a double-acting hydraulic bufier mechanism having afixed element attached to one of said members and a moving elementattached to the other of said members; cooperating stop means on saidmembers permitting limited longitudinal movement between the elements ofsaid hydraulic mechanism; light-duty resilient means acting in at leastone longitudinal direction to urge said sliding member to a neutralposition between the limits of travel of the elements of said hydraulicmechanism; heavy-duty resilient means mounted on said fixed center sillmember; and lost motion coupler means coupling said heavy-duty resilientmeans to said sliding member over both of the terminal portions of thetotal permitted longitudinal movement of said sliding member, said lostmotion coupler means uncoupling said heavy-duty resilient means fromsaid sliding member over an intermediate portion of the total permittedmovement of said sliding member.

4. In a railway car having a center sill member affixed to the car, adraft assembly comprising: a housing supported and longitudinallyslidable in said center sill member; a car coupler attached to saidhousing; a doubleacting hydraulic buffer mechanism mounted within saidhousing and having a piston rod extending rearwardly therefrom; meansanchoring the rearward end of said piston rod to said fixed center sillmember; cooperating stop means on said center sill member and saidhousing permitting limited longitudinal movement of said housing in saidcenter sill member; light-duty resilient means coupled to said fixedcenter sill member and engaging said housin' acting in at least onelongitudinal direction to urge said housing to a neutral positionbetween the limits of movement of said housing; heavy-duty resilientmeans mounted on said fixed center sill member; and lost motion couplermeans coupling said heavy-duty re- 13 silient means to said housing overthe terminal portions of the total permitted longitudinal movement ofsaid housing, said lost motion coupler means uncoupling said heavy-dutyresilient means from said housing over an intermediate portion of thetotal permitted movement of said housing.

5. In the combination defined in claim 4, wherein the said heavy-dutyresilient means comprises a helical spring.

6. In a railway car having a center sill member afiixed to the car, adraft assembly comprising: a housing supported and longitudinallyslida'ble in said center sill member; a car coupler attached to saidhousing; a doubleacting hydraulic buffer mechanism mounted within saidhousing and having a piston rod extending rearwardly therefrom; meansanchoring the rearward end of said piston rod to said fixed center sillmember; cooperating stop means carried by said fixed center sill memberand by said housing limiting rearward movement of said housing in saidcenter sill member; said center sill member providing opposedlongitudinally extending slot means therein and said housing providingnarrower opposed slot means aligned with the slot means in said centersill member; a key extending through the aligned slot means in saidhousing and said center sill member, said key limiting forward movementof said housing in said center sill member by abutment with theforwardends of the slot means in said center sill member; heavyduty resilientmeans mounted on said fixed center sill member; a lost motion couplermember engaging. said heavy-duty resilient means, said coupler memberproviding a longitudinally extending slot receiving said key, said slotbeing shorter than the slots in said fixed center sill member and longerthan the slots in said housing, to engage said heavy-duty resilientmeans with said housing through said key only near either end of thelimit of movement of said housing in said center sill member; andlight-duty resilient means coupled to said fixed center sill member andengaging said housing, acting in at least one longitudinal direction tourge said housing to a neutral position between the limits of movementof said housing.

7. In a railway car having a center sill member afiixed to the car, adraft assembly comprising: a housing supported and longitudinallyslidable in said center sill member; a car coupler attached to saidhousing; a doubleacting hydraulic butler mechanism mounted within saidhousing and having a piston rod extending rearwardly therefrom; meansanchoring the rearward end of said piston rod to said fixed center sillmember; cooperating stop means carried by said fixed center sill memberand by said housing limiting rearward movement of said housing in saidcenter sill member; said center sill member providing upper opposed andlower opposed longitudinally extending slot means therein and saidhousing providing upper and lower opposed slot means aligned with andshorter than the slot means in said center sill member; a key extendingthrough each of the upper and lower aligned slot means in said housingand center sill member limiting forward movement of said housing byabutment with the forward ends of said slot means in said center sillmember; heavy-duty resilent means mounted on said fixed center sillmember; a lost motion coupler member attached to said heavy-dutyresilient means, said coupler member providing a pair of longitudinallyextending slots therein receiving said keys, said slots being shorterthan the slots in said fixed center sill member and longer than theslots in said housing, to engage said heavy-duty resilient means withsaid housing through said keys only near either end of the limit ofmovement of said housing in said center sill member; and light-dutyresilient means coupled to said fixed center sill member and engagingsaid housing, acting in at least one longitudinal direction to urge saidhousing to a neutral position between the limits of movement of saidhousing. 8. In a railway car having a center sill member aflixed to thecar, a draft assembly comprising: a housing supported and longitudinallyslidable in said center sill member; a car coupler attached to saidhousing; a doubleacting hydraulic bufier mechanism mounted within saidhousing and having a piston rod extending rearwardly therefrom; meansanchoring the rearward end of said piston rod to said fixed center sillmember; cooperating stop means carried by said fixed center sill memberand by said housing limiting rearward movement of said housing in saidcenter sill member; said center sill member providing upper opposed andlower opposed longitu dinally extending slot means therein and saidhousing providing shorter upper and lower opposed slot means alignedwith the slot means in said center sill member; a key extending througheach of the upper and lower aligned slot means in said housing andcenter sill member limiting forward movement of said housing by abutmentwith the forward ends of said slot means in said center sill; a pair ofheavy-duty coil springs, one mounted on each exterior side wall of saidfixed center sill rearwardly of said keys; a pair of lost motion couplermembers, one engaging each of said heavy-duty coil springs, each saidcoupler member providing a pair of longitudinally extending slotsreceiving the ends of said keys, said slots being shorter than the slotsin said fixed center sill and longer than the slots in said housing, tocouple said heavy-duty coil spring means with said housing through saidkeys only near either end of the limit of movement of said housing insaid center sill member; and light-duty spring means coupled to saidfixed center sill member and engaging said housing, acting in at leastone longitudinal direction to urge said housing to a neutral positionbetween the limits of movement of said housing.

9. A secondary shock absorbing assembly for railway cars comprising: abox-like unitary structure having spaced apart end walls serving asbracket members, said bracket members providing central openingstherein; a collar member abutting the inside -wall of each of saidbracket members, each of said collar members providing a centralopening. therein aligned with the opening provided in said bracketmembers; a helical compression spring mounted in said structure betweensaid collar members; a lost motion coupler plate having a shaftextending longitudinally therefrom through the aligned openings in saidbracket and collar members, said coupler plate providing alongitudinally extending slot therein for receiving a draft gear key;and engaging means provided on said shaft for engaging each of saidcollar members to compress said spring upon longitudinal movement ofsaid coupler plate.

10. A secondary shock absorbing assembly for railway cars comprising: abox-like unitary structure having spaced apart end walls serving asbracket members, said bracket members providing central openingstherein; a spring compressor member abutting the inside wall of each ofsaid bracket members, said spring compressors having a reduced portionextending rearwardly therefrom through the openings provided in saidbracket members; a helical compression spring mounted in said structurebetween said compressor members; a lost motion coupler yoke having acutout section therein fitting loosely over said structure with the endWalls of said yoke substantially abutting the outer ends of saidcompressor members, and said yoke providing a longitudinally extendingslot in one end thereof for receiving a draft gear key. I t

No references cited.

